A randomized, blinded trial in post menopausal women with cornaornary artery disease to test the hypothesis, among 2340 women who have a uterus, that those randomized to receive estrogen-progestin replacement therapy (Premanrin .625 mg daily plus medroxygrprogesterone acetate 2.5 mg daily) have the same frequency on new CHD events (myocardial infarction and CHD death) as those randomized to placebo.